I've pretty extensively researched tons of examples of moire on the 5dsr vs 5ds from people who owned both and tried to find moire, which is the perfect comparison since they are identical besides the canceling filter.I am a long time anti-anti-alias filter proponent. You can see from one of my previous posts that the resolution of the R5 sensor is only slightly below that of the acclaimed Z7/D850 sensor which has the same pixel count but without the AA-filter. So, Canon could increase the resolution a bit. In return, I have had none of the infrequent examples of Moire I have had with the 5DSR or D850 when using the R5. I believe that Canon retains the AA-filter as feature for video users as Moire affects video recordings - the 5DSR was not aimed at video. So, I can live with the very low level of blurring from the R5 sensor.
The only cases i could find of significant moire on the 5dsr also showed significant moire on the 5ds, just a bit less of it. So it's not like you are avoiding moire, you are just making it a bit less prominent in some select (<1%) cases in exchange for all of your pictures being less sharp. This was useful for stills at 20mp but not so much at 51mp.
For stills I don't think that's worth the tradeoff and video is probably why they put it in the R5 - in video it is definitely still useful at 45mp. I am betting the R5s won't have an AA filter. The current 5DsR runout / closeout demonstrates the 5DsR was a much more popular camera as they aren't even bothering making any 5Ds anymore with the remaining sensors.